Class 8 light subjective questions

Multiple Choice Questions

1. Part of the eye which controls the light entering is called
   • (a) iris
   • (b) cornea
   • (c) lens
   • (d) retina
2. We can see a non-luminous object when light:
   • (a) emitted by the object falls on the eye.
   • (b) is reflected from the object towards our eye.
   • (c) completely passes through the object.
   • (d) gets completely absorbed by the object.
3. Light is falling on surface S₁, S₂, S₃ as shown in Fig.16.1.
   
   • (a) S₁ only
   • (b) S₁ and S₂ only
   • (c) S₂ and S₃
   • (d) all the three surfaces
4. A tiny mirror M is fixed on a piece of cardboard placed on a table. The cardboard is illuminated by light from a bulb. The position of eye with respect to position of bulb is shown in Fig.16.2 as A, B, C and D. In which position mirror will be visible?
   
   • a. A
   • b. B
   • c. C
   • d. D
5. A small hole P is made in a piece of cardboard. The hole is illuminated by a torch as shown in Fig. 16.3. The pencil of light coming out of the hole falls on a mirror.
   
   • (a) A
   • (b) B
   • (c) C
   • (d) D
6. Two mirrors A and B are placed at right angles to each other as shown in Fig.16.4.
   
   • (a) 250
   • (b) 500
   • (c) 650
   • (d) 1150
7. Which of the following statements is correct regarding rods and cones in the human eye?
   • (a) Cones are sensitive to dim light.
   • (b) Cones are sensitive to bright light.
   • (c) Rods are sensitive to bright light.
   • (d) Rods can sense colour.
8. In the figure of the human eye (Fig.16.5), the cornea is represented by the letter
   
   • (a) A
   • (b) B
   • (c) C
   • (d) D

Very Short Answer Type Questions

1. Name the part of the eye which gives colour to the eyes.
2. Boojho while waving his hand very fast in front of his eyes, observes that his fingers appear blurred. What could be the reason for it?
3. How many times is a ray of light reflected by two plane mirrors placed parallel and facing each other?
4. The angle between incident ray and reflected ray is 60°. What is the value of angle of incidence?
5. The distance between the object and its image formed by a plane mirror appears to be 24 cm. What is the distance between the mirror and the object?